Use of fluorescent probes in fluorescence microscopy
Fluorescent probes are molecules with high-affinity for certain cell structures that are bound to a fluorophore. Some of the most common fluorophores used in fluorescent probes are Rhodamine or Fluorescein isothiocyanate (FITC).
For instance, Phalloidin is a highly toxic molecule produced by a mushroom, which binds to the actin cytoskeleton, preventing its depolarization, thereby killing the cell. The high specificity to actin filaments can be used to stain the cytoskeleton by chemically cross-linking Phalloidin with a fluorophore such as rhodamine to visualize the structure in the fluorescence microscope.